Standing before a forest of microphones after former Illinois Gov. Rod Blagojevich announced that he wouldn't testify at his corruption trial as he'd promised, defense lawyers Sam Adam Sr. and Sam Adam Jr. wasted no time explaining why their client opted for the rare-for-Blagojevich move of keeping his mouth shut.

Sam Sr. told him to.

"Well, he didn't (testify) ... because he took my advice and it's still my advice and someday we will know the answer of who's right and wrong," the 74-year-old father, a grizzled criminal attorney, told reporters at the federal courthouse.

"It came down to an argument between an old bull and a young toad," the younger attorney added. "The old bull won."

High-profile clients, from O.J. Simpson to former Illinois Gov. George Ryan, rarely take the stand. So questions remained about whether this was a strategy Blagojevich's attorneys had long agreed on as he fights charges including that he tried to sell an appointment to President Barack Obama's old Senate seat.

In his opening statements last month, Sam Jr. — just 37 and a rising star in legal circles — pointed dramatically to his client across the courtroom and pledged to jurors he'd take the stand. So in his closing sometime next week, jurors may expect him to give some explanation for why the ousted governor didn't testify.

On Wednesday, he acknowledged the quandary about his vow to jurors — without offering a clear solution.

"Look, did I tell them this?" he said about the pledge, his voicing rising. "Is there a harm when I go back and look at them on Monday and say, 'Look, I promised you. He wasn't there.' Certainly. We're adults. We know it."

Sam Jr. has gained a reputation as a fiery courtroom orator whose closing argument two years ago preceded R&B singer R. Kelly's acquittal on child pornography charges. His father was also on the defense team in that case.

The father and son bantered before reporters on Wednesday, joking about each other, in turn smiling and shaking their heads when the other was speaking, sticking to a script familiar to those who have followed them.

Blagojevich portrayed himself in comments to reporters as caught between the two — leaning toward Sam Jr.'s argument in favor of testifying, but reluctantly accepting Sam Sr.'s counsel that he shouldn't.

"Sam Jr. still at this moment wanted me to testify and frankly so did I," Blagojevich said about their late-night discussions Monday. "Sam Adam Sr.'s most compelling argument, and I believe the one that swayed me, was that the government in their case proved my innocence ... there was nothing further for us to add."

Only a few hours earlier, a calm and confident Blagojevich stood before U.S. District Judge James B. Zagel.

"Is it your decision not to testify?" Zagel asked.

"It is my decision," Blagojevich responded, nodding slightly.

His attorneys rested his defense without calling a single witness, and prosecutors rested theirs.

Blagojevich, 53, has pleaded not guilty to scheming to sell or trade the Senate seat and to plotting to launch a racketeering operation in the governor's office. His brother, Robert Blagojevich, 54, of Nashville, Tenn., has pleaded not guilty to charges including taking part in the alleged Senate seat scheme.

Trial lawyers said Blagojevich's decision may have caught prosecutors off guard and could force them to adjust their strategy, which included cross-examining Blagojevich and potentially offering tough rebuttal witnesses.

"I think the government was outfoxed by him," said Leonard Cavise, a DePaul University law professor.

Other observers said Blagojevich's move is a high-risk gamble that spared him from a possible ordeal on the witness stand but could backfire with the jury.

"I think the cross-examination would have been devastating," said Ron Safer, former head of the criminal division of the U.S. attorney's office and now in private practice. "But I think the silence is also devastating."

Copyright 2010 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.